Information associated with vibration measurement and associated mechanical deformation can be important for a variety of medical and non-medical applications. One example is its use for determining the biomechanical characteristics of the bones or ossicles of the middle ear. The middle ear bones can transmit the vibrations of the tympanic membranes to the inner ear, where the mechanical motion is translated into neural response. The ability to measure the vibrations of the ossicles at the sound frequency can be useful for the diagnosis of many types of hearing impairment. Currently, the measurement of the vibrations in the middle ear requires an exposure of the middle ear by surgery. A minimally invasive tool for measuring bone vibration is therefore desired, reducing risk and improving diagnosis accuracy.
Spectrally encoded endoscopy (SEE) is a technique that can use wavelength to encode spatial information on a sample, thus allowing for high quality imaging to be performed through small diameter endoscopic probes. Using interferometery, SEE can use the phase of the reflected light to encode depth, and distance. By using a high speed spectral measurement at rates, e.g., higher than the auditory frequency, SEE can measure small spectral phase differences that are associated with sound vibrations. Without any form of scanning in the distal end of the probe, SEE can measure axial motion along one transverse line.